45. I spent half an hour _____ this difficult math problem.
　A. having worked on      B. to work on　　C. on work D. working on 
答案：D。spend（some time ，some money） in doing sth（on sth），因此选D。He spent his life writing the book.他花一生的时间写这本书。He spends more time on sports than on studies. 他花在体育运动上的时间比花在学习上的时间多。

46. The medicine can prevent you _____.
　A. from getting drunk　　B. got drunk　　C. get drunk　　D. being drunk
答案：A。prevent sb from doing sth 阻止，阻挡。The rain prevented us from playing tennis.一场雨使我们不能打网球。

47. Her suggestion that everybody _____ was not appreciated.
　A. sing a song　　B. sang a song　　C. sung a song　　D. singing a song 
答案：A。本句测试虚拟语气在同位从句中的用法。在suggestion, proposal, request，order 等名词后面的表语从句和同位语从句中，用（should ）+动词原形，表示虚拟，should常常省略。又如：My suggestion is that we （should） send a few people to help the other groups.我的建议是我们派几个人去帮助其他的小组。

48. I have taken many photos. I'm going to get the film _____.
　A. being developed　　B. developing　　C. developed　　D. to be developed 
答案：C。过去分词在动词have, get两词后面作宾补时,常常表示这个动作不是由主语完成的,而是由别人完成的。You’d better have （get） the dangerous building pulled down.你最好叫别人把这座危楼推倒了。He had some pictures taken in the park.他在公园里照了几张像。(别人给他照的

49. _____ the last one, I answered all the questions.
　A. Except　　B. Except for　　C. Besides　　D. In addition to
答案：B。except for：指对结论的修正。如：本句的意思“我回答了所有的问题， 除了最后一个。”因此，“except for the last one”是对前一句的修正。又如 The carpet is good except for its price.地毯很好，只是价格太贵。His composition is very good except for a few spelling mistakes.他的作文很好，除了几处拼写错误以外。except：除了…之外。besides和in addition to 除了…（包括）

50. He suggested _____ a lecture given by Professor White on English language learning.
　A. me to attend　　B. my attending　　C. my attention　　D. me attending 
答案：B。suggest 建议，推荐。suggest 后面要跟动名词做宾语；或者用物主代词+动名词。如：He suggested our returning home as soon as possible.他建议我们快回家。He suggested （to us） that an exception （should）be made.他（向我们）建议破例处理。因此选择B。

51. Not always _____ they want to.
A. people can do what　B. people cannot do what　
C. can people do what D. can't people do what 
答案：C。否定词放在句首，句子倒装。否定词+助动词 或（be）动词+主语。常用的否定词有：barely, hardly, scarcely, not, never, little 等。Barely does he have enough money to live on.他几乎没有足够的钱为生。Little did I think that I would lose the game.我根本没有想到我会输掉这场比赛。

52. “Good — bye, Miss Liu. I'm very pleased _____.”
　A. to meet you　　B. to have met you　　C. meeting you　　D. having met you